Seeinstructions): The proposed project focuses on understanding the effects of early life stress (ELS) among toddler-aged foster children. Psychosocial adjustment in toddlerhood has been shown in prior longitudinal studies to be associated with emotional and attentional outcomes later in development, and foster toddlers are known to be at risk for poor psychosocial adjustment. We use ELS as a framework to characterize the early adverse care conditions common to foster children, specifically a history of maltreatment and caregiver transitions. We integrate basic developmental behavioral neuroscience from nonhuman primate and human models to (a) increase our understanding of the neurobiological and behavioral impacts of early adverse care and (b) identify subsequent caregiving experiences that support recovery from early adverse care. The central hypothesis for this project is that ELS in the form of early adverse care results in chronic activation and counter-regulatory down-regulation of the stress-response system, shapes more reactive threat-response system, and impacts the development of emotion- and attention-regulatory systems. Inasmuch as these neural systems are somewhat plastic during early life, improved care might normalize their functioning. However, because young foster children exposed to early adverse care often confront caregivers with disruptive behavior problems and disordered attachment behaviors, therapeutic parenting must involve reducing behavior problems through consistent, nonhostile structure/limit setting and providing nurturance the child needs but may not signal. Even so, children exposed to severe, prolonged early adverse care might sustain neurobiological vulnerabilities that increase risk of pathology long after care conditions improve. In the proposed project, we will recruit 150 foster toddlers (ages 18-30 months) entering a new foster care placement. Three waves of data collection are plannedat 1 month postplacement and at 6 and 12 months after entering the project. Data collection in the first two waves will emphasize the functioning of stress- and threat-response systems and caregiver-child interactions within the foster care environment. Data collection at the third wave will emphasize psychosocial outcomes, specifically emotion- and attention-regulatory problems. The resulting dataset will allow for multivariate statistical modeling to test hypotheses emanating from the Center's overarching conceptual model. RELEVANCE (See instructions): Foster children are at significant risk for emotional and attentional problems. In this project, we will examine the effect of early adverse care experiences, specifically maltreatment and multiple caregiver transitions, and the impact of variations in caregiving within the foster care environment on the brain systems involved in emotion and attention. The knowledge generated by this project will allow us to develop more precise and targeted interventions for foster children and other children exposed to early adverse care.